Lookout in the top tier is certainly controversial, but I understand the logic if you really REALLY value early trashing/sifting, but the one I don't understand is Explorer in a tier over Cutpurse and Merchant Ship. They're all iffy terminal payload, but cutpurse is cheaper with a useful early game attack, and merchant ship is obviously a duration, but explorer sticks you with a silver that you may or may not want, or possibly a gold that you may or may not want. What's the reasoning behind that distinction?

I think if anything is S-tier here, it's Vampire. Necromancer in D is super strange, I think that is a solid A. I don't know how Conclave is S-tier, that's just some middle ground between Squire and Festival, and those are not strong cards.

Maybe true, but I did say "in this respect" - i.e. considering the specific objection that Lookout is too slow a trasher. Just buy more than one! (Lookout/Lookout is actually a pretty nice opening for thinning quickly and being pretty likely to hit $5 before second shuffle on a board where that's important.)